I could likely sum up this entire review by simply stating the title of the game in question: Yet Another Zombie Defense. Intended as a sideways joke at the ridiculous number of zombie themed games flooding the market, it extends beyond the name to every aspect of the game, resulting in a bland and unimaginative isometric shooter that even for the low price is hardly worth a second glance.
If you've ever played a wave based survival shooter you already know exactly how YAZD functions. Enemies come at you in increasingly difficult swarms, which you then counter by buying guns and defense in between rounds. Rinse, repeat, and try to stay alive as long as you can. It's a formula that's been done dozens of times over, but when executed properly can be immensely addictive and rewarding.
You can probably see where I'm going with this, so I'll just spell it out: YAZD doesn't get it right. A surface summarization of the many games that inspired it, it has the right pieces to potentially make a great game but doesn't know how to use them effectively. Progression is severely limited and uninteresting, with only a handful of unimpressive guns to choose from and even fewer defenses, as well as no upgrade system or other means to provide something to keep playing for beyond a highscore. Enemies are repetitive to far too great a degree, making for a dull experience after the first few waves as you begin to go through the motions, and the banal presentation leaves a great deal to be desired.
To be perfectly fair, YAZD isn't broken on any fundamental level, it's just not fun. Everything it attempts has already been done infinitely better in so many other games, that I can't bring myself to recommend it for even a quick look. There's an argument to be made for it being cheap so expectations are obviously lowered, but personally I would recommend spending a bit more and getting something more polished and deserving of your time. You might be able to squeeze an hour of enjoyment out of it with a friend if you really try, but that doesn't make up Yet Another Zombie Defense being as hollow and lifeless as the undead it pits against you.